PPP Multilink Protocol (“MP” or “Multilink” or “Multilink Protocol”) provides a method for splitting, recombining, and sequencing datagrams across multiple logical data links (that is, interfaces). A frame is a unit of transmission in the data link layer, consisting of a frame header and a packet. An Internet Protocol (“IP”) datagram is a unit of end-to-end transmission in the IP protocol. It consists of an IP header followed by the Transmission Control Protocol (“TCP”) segment. A packet is a generic way to refer to datagrams that are either whole (that is, an IP datagram) or fragmented (that is, an IP datagram fragment). Multilink allows packets to be fragmented and the fragments to be sent over multiple PPP links to the same remote address resulting in aggregation of traffic across multiple links for extra bandwidth and redundancy.
Multilink with multi-class extensions (“Multilink-Extension”) is typically used to provide Quality of Service (“QOS”) to data traffic by using fragmentation and interleaving of packets across a multi-link interface. Thus, Multilink-Extension allows a sender to fragment packets of various priorities into multiple classes of fragments, allowing high-priority packets to be sent between fragments of lower priorities.